Editor's note: While most of the “black diamonds” you’ll see on the market are enhanced, true black diamonds are rare but do exist. There’s even a famous one called the Black Orlov (named for a Russian princess) that has at times been on display at museums in both New York and London. Elegant and a bit mysterious, black diamonds are the subtly glittering introvert to their more traditional and ubiquitous cousin. Show your good taste with a lovely Black Diamond wallpaper!